LEDs, in contrast to the traditional illumination lamps, e.g. the incandescent lamp, have the advantages of comparatively saving electricity and having a longer life-span, and are thus increasingly widely used as the illumination lamps. A circuit diagram of a traditional LED driver having a filter circuit is shown in FIG. 1. In FIG. 1, the driver includes an AC input power source AC, a bridge rectifier having rectifying diodes D1-D4, a filter circuit having an inductor L1 and a capacitor C1 and an LED module.
The traditional LED driver having the filter circuit as shown in FIG. 1 has a relatively lower power factor (PF), a relatively larger total harmonic distortion (THD) and a relatively lower efficiency. Thus, developing a method to improve the traditional LED driver to make it have a relatively higher PF, a relatively lower THD and a relatively higher efficiency to further save energy and exhibit maximum effectiveness is worthy of further research and improvement.
Keeping the drawbacks of the prior arts in mind, and employing experiments and research heartily and persistently, the applicant has finally conceived an LED driver having a compensation capacitor set.